Thanks so very much for the reminder of the IL Marriages at www.cyberdriveillinois.com/departments/archives/databases.ht... which I had forgotten. It turns out that Minnie Ann James married James Raymond Dupuy. Also, Piatt Co IL deaths are part of the IL Illinois Statewide Death Index, Pre–1916 Dec.1877–Dec. 1915, however no death for James Raymond, nor for any Dupuy or Dupay that could possibly be him. I expect his death occurred elsewhere as I am unable to find Minnie nor James Dupuy in the 1900 Census.
Thanks for your help. We will leave this as unsolved for the time being.